Egomane is giving very sound advice here on all points, OP; listen to him.
Do not drop below a 260, spring for a 270 if in any way possible. Nvidia cards are fine, but don't buy the hype. If you think their logo appears everywhere, just remember,
both of the latest next gen consoles use AMD hardware
But that's neither here nor there. Nvidia has never owned the value segment, at least not for a long, long time, and they probably never will for a long, long time. If you had the money for a 970 I'd tell you to heavily consider a 970, but you don't, and that's fine. That plants you firmly in the territory where AMD owns the market, offering better cards with more memory and performance for the same or fewer dollars.
The 260X matches or outperforms the GTX 750, even when it's a stock 260X and a OCed 750, and you can get an OCed 260X. In fact, both the MSI and Sapphire 260Xs on Overclockers are overclocked.
http://www.techpower...R7_260X/26.html
In short, I see no reason to consider going Nvidia.
Also, I know it's a tiny stretch for the budget, but really, a 270 is a decent jump. Yeah you're paying 30 quid more, but you're getting that much performance out of it, and it's only 9 over your stated budget
http://www.overclock...rodid=GX-169-PC
Edited by Catamount, 17 November 2014 - 08:37 AM.